- proterozoic - formed in the later of two divisions of the Precambrian era; "proterozoic life forms"
Antonym: middle (indirect, via late, early)
Antonym: late (indirect, via early, middle)
- Proterozoic, Proterozoic eon, Proterozoic aeon - from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms
--1 is a kind of eon, aeon
--1 is a part ofPrecambrian, Precambrian eon, Precambrian aeon, Precambrian period